But anyways, he's dead imo, and no reason to bring him back. We see him dead for a reason. When would Harvey's body in Two-face form have time to run away, and why would they never mention that during the tribute scene?

The reason to bring him back is because he is one of the most interesting villians in the Batman universe... second to only the Joker. There is a reason why Dent's death is ambiguous. And also why they never fully confirmed it... all answers on the question of Dent's death have been semi-confirmed as you put it. Why wouldn't they mention it in the tribute scene? Because of the element of surprise.